Impaired lymphocyte reactivity measured by immune function testing in untransplanted patients with cirrhosis.

The immune function test is an integrated measure of total mitogen-inducible CD4(+) T cell metabolic activity in the peripheral blood, and it is used to guide the dosing of immunosuppressive medications after solid organ transplantation. Recently, low CD4(+) T cell metabolic activity due to pharmacologic immunosuppression has been linked to rapidly progressive cirrhosis in hepatitis C virus (HCV)-infected liver transplant recipients. We speculate that either cirrhosis or HCV might adversely affect the CD4(+) T cell reactivity even in the absence of immunosuppressive medications. We thus performed this assay on a cohort of untransplanted hepatology patients who were not taking immunomodulatory drugs. Low mitogen-stimulated CD4(+) T cell metabolic reactivity was more commonly seen in untransplanted patients with HCV cirrhosis or with cirrhosis due to other causes but not in control patients or in those with chronic HCV in the absence of cirrhosis. The lowest mean CD4(+) T cell reactivities were seen in patients with both cirrhosis and HCV. Caution should be exercised when immune function test results are used to guide immunomodulatory therapy in transplant recipients with suspected cirrhosis, as low immune function test results may be a consequence of hepatic cirrhosis or of pharmacologic immunosuppression.

Nonresponse to interferon-α based treatment for chronic hepatitis C infection is associated with increased hazard of cirrhosis.

BACKGROUND: The long-term consequences of unsuccessful interferon-α based hepatitis C treatment on liver disease progression and survival have not been fully explored. METHODS AND FINDINGS: We performed retrospective analyses to assess long-term clinical outcomes among treated and untreated patients with hepatitis C virus in two independent cohorts from a United States Veterans Affairs Medical Center and a University Teaching Hospital. Eligible patients underwent liver biopsy during consideration for interferon-α based treatment between 1992 and 2007. They were assessed for the probability of developing cirrhosis and of dying during follow-up using Cox proportional hazards models, stratified by pretreatment liver fibrosis stage and adjusted for known risk factors for cirrhosis and characteristics affecting treatment selection. The major predictor was a time-dependent covariate for treatment outcome among four patient groups: 1) patients with sustained virological response to treatment; 2) treatment relapsers; 3) treatment nonresponders; and 4) never treated patients. Treatment nonresponders in both cohorts had a statistically significantly increased hazard of cirrhosis compared to never treated patients, as stratified by pretreatment liver fibrosis stage and adjusted for clinical and psychosocial risk factors that disproportionately affect patients who were ineligible for treatment (Veterans Affairs HR=2.35, CI 1.18-4.69, mean follow-up 10 years, and University Hospital HR=5.90, CI 1.50-23.24, mean follow-up 7.7 years). Despite their increased risk for liver disease progression, the overall survival of nonresponders in both cohorts was not significantly different from that of never treated patients. CONCLUSION: These unexpected findings suggest that patients who receive interferon-α based therapies but fail to clear the hepatitis C virus may have an increased hazard of cirrhosis compared to untreated patients.

Outcomes of extended-infusion piperacillin-tazobactam: a retrospective analysis of critically ill patients.

Studies evaluating the outcomes of an extended-infusion (EI) piperacillin-tazobactam dosing strategy in specific cohorts of critically ill patients are lacking. A retrospective, pre-implementation and post-implementation study of 148 critically ill patients was conducted to compare EI and traditional infusion piperacillin-tazobactam. In this retrospective study, the EI piperacillin-tazobactam dosing strategy was associated with improved 30-day mortality. EI piperacillin-tazobactam may be an effective alternative to TI of piperacillin-tazobactam among critically ill patients treated for suspected gram-negative infections.

Spider minor ampullate silk proteins are constituents of prey wrapping silk in the cob weaver Latrodectus hesperus.

Spiders spin high performance fibers with diverse biological functions and mechanical properties. Molecular and biochemical studies of spider prey wrapping silks have revealed the presence of the aciniform silk fibroin AcSp1-like. In our studies we demonstrate the presence of a second distinct polypeptide present within prey wrapping silk. Combining matrix-assisted laser desorption ionization tandem time-of-flight mass spectrometry and reverse genetics, we have isolated a novel gene called MiSp1-like and demonstrate that its protein product is a constituent of prey wrap silks from the black widow spider, Latrodectus hesperus. BLAST searches of the NCBInr protein database using the amino acid sequence of MiSp1-like revealed similarity to the conserved C-terminal domain of silk family members. In particular, MiSp1-like showed the highest degree of sequence similarity to the nonrepetitive C-termini of published orb-weaver minor ampullate fibroin molecules. Analysis of the internal amino acid sequence of the black widow MiSp1-like revealed polyalanine stretches interrupted by glycine residues and glycine-alanine couplets within MiSp1-like as well as repeats of the heptameric sequence AGGYGQG. Real-time quantitative PCR analysis demonstrates that the MiSp1-like gene displays a minor ampullate gland-restricted pattern of expression. Furthermore, amino acid composition analysis, coupled with scanning electron microscopy of raw wrapping silk, supports the assertion that minor ampullate silks are important constituents of black widow spider prey wrap silk. Collectively, our findings provide direct molecular evidence for the involvement of minor ampullate fibroins in swathing silks and suggest composite materials play an important role in the wrap attack process for cob-weavers.

Aciniform spidroin, a constituent of egg case sacs and wrapping silk fibers from the black widow spider Latrodectus hesperus.

Spiders produce high performance fibers with diverse mechanical properties and biological functions. Molecular and biochemical studies of spider egg case silk have revealed that the main constituent of the large diameter fiber contains the fibroin TuSp1. Here we demonstrate by SDS-PAGE and protein silver staining the presence of a distinct approximately 300-kDa polypeptide that is found in solubilized egg case sacs. Combining matrix-assisted laser desorption ionization tandem time-of-flight mass spectrometry and reverse genetics, we have isolated a novel gene called AcSp1-like and demonstrate that its protein product is assembled into the small diameter fibers of egg case sacs and wrapping silks from the black widow spider, Latrodectus hesperus. BLAST searches of the NCBInr protein data base using the amino acid sequence of AcSp1-like revealed similarity to AcSp1, an inferred protein proposed to be a component of wrapping silk. However, the AcSp1-like protein was found to display more nonuniformity in its internal iterated repeat modules than the putative AcSp1 fibroin. Real time quantitative PCR analysis demonstrates that the AcSp1-like gene displays an aciniform gland-restricted pattern of expression. The amino acid composition of the fibroins extracted from the luminal contents of the aciniform glands was remarkably similar to the predicted amino acid composition of the AcSp1-like protein, which supports the assertion that AcSp1-like protein represents the major constituent stored within the aciniform gland. Collectively, our findings provide the first direct molecular evidence for the involvement of the aciniform gland in the production of a common fibroin that is assembled into the small diameter threads of egg case and wrapping silk of cob weavers.